ANSI MSS SP-44:2019 pdf download.Steel Pipeline Flanges.
1.1 General ANSI MSS SP-44 Practice covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for steel pipeline flanges. The welding neck type flanges shall be forged steel, and the blind flanges may be made from either forged steel or from steel plate.
1.1.1 Dimensional and tolerance requirements for NPS 10 and smaller are provided by reference to ASME B 16.5. When such flanges are produced from materials meeting Table 2 requirements, and meet all other stipulations of ANSI MSS SP-44 Practice, then they shall be considered as complying therewith.
1.1.2 ANSI MSS SP-44 Practice covers two Product Specification Levels (PSL). If no PSL is specified, material shall be supplied as PSLI with the standard requirements as are contained in the body of this Standard Practice. If PSL2 is specified, the material shall meet the additional requirements specified in Supplementary Requirement SR-18 (see Annex D/D.l).
1.2 References
1.2.1 Referenced Standards The standards and specifications incorporated by reference in ANSI MSS SP-44 Practice are shown in Annex E, for convenience of identifying edition number, date, and source of supply.
A flange made in conformance with a prior edition of referenced standards or specifications and is in all other respects conforming to this Standard Practice, will be considered to be in conformance even though the edition referenced may have changed in a subsequent revision of ANSI MSS SP-44 Practice.
1.2.2 codes and Regulations A flange used under the jurisdiction of the ASME Boiler and Pressure Vessel Code (BPVC), the ANSI-approved ASME Code for Pressure Piping, or Governmental Regulations, is subject to any limitation of that code or regulation. This includes any maximum temperature limitation for a material, or rule governing the use of a material at a low temperature.
1.3 Relevant Units ANSI MSS SP-44 Practice states values in both SI (metric) and U.S. Customary units. As an exception, diameters of bolts and flange bolt holes in all tables are expressed in inch units (U.S. Customary) only. Each of these systems of units are to be regarded separately as the standard and cannot be combined. Within the text, the SI (metric) units are listed first and included in main tables with U.S. Customary units shown in parentheses, combined tables, or in separate annex tables; however, this does not imply primacy of SI (metric) units. The values and tolerances stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Except for diameter of bolts and flange bolt holes, combining values from the two systems constitutes nonconformance with the Standard Practice.
2. DENOTATIONS
2.1 Pressure-Temperature Ratings Flanges covered by this Standard Practice shall be designated as one of the following: Class 150, 300, 400, 600, or 900. The pressure-temperature ratings in Table 4 are in SI (metric) and U.S. Customary.
2.2 Size The term “NPS”, followed by a dimensionless number, is the designation for a corresponding nominal pipe size. NPS is a separate designation system; however, it has a relation to the reference Nominal Diameter, “DN”, which is used in international standards.ANSI MSS SP-44 pdf download.